Adding Basic AI to support single player mode

After having so many problems with using Parsc, we decided to add in AI-player to enable single player mode.

Due to insufficient time, we are unable to make a beatiful AI logic with accurate data and algorithm behind. However, we use Random and Position-Checking to make a clever/lucky-enough AI that enables the single player mode.

We may have a better AI algorithm if we have more time to work on it. (Personally I would keep working on this concept even the course is ended)